Intravaginal contraceptive devices have become widely accepted as a safe and reliable method of birth control, as well as for the prevention of sexually transmitted diseases. Some devices take the form of a porous, absorbent sponge which is impregnated with spermicidal and/or bacteriocidal agents. Other devices commonly take the form of a diaphragm, made of an elastic film material such as latex, having an annular rim with a resilient metal spring, such as a coiled or leaf spring or flat spring or metal band, incorporated therein.
The metal springs for contraceptive diaphragms are difficult to make, since they must be resilient for bending and durable enough to last with repeated use. For a molded latex diaphragm, the spring is typically a coiled wire that is placed on one mold-half, and latex is poured in the mold so that the spring becomes embedded therein. For a rolled latex diaphragm, a latex sleeve is formed on a mold element by dipping it in the latex, then a spring is placed over the mold base and rolled up in the latex by hand until it is secured therein.
The conventional methods of fabricating contraceptive diaphragms are therefore quite complex, costly, and/or labor-intensive. Furthermore, the metal springs often have coatings of heavy metals, such as cadmium and zinc, for corrosion resistance, which may present a risk of allergic or toxic effects. It is therefore a principal object of the invention to provide a contraceptive diaphragm which does not employ a metal spring and which is simple and inexpensive to make.